Probably root damage when it was dug for transplanting

Resin

Not sure what caused browning, but the same thing happened to us when we removed a large spruce that provided some wind protection. The top third of our tree browned and we cut it off, planning to prune as a large shrub, as an arborist told us it wouldn't form a new leader. Two years later, it looked pretty much as it had before the drastic pruning. BTW, the 6 ft. section we removed was totally dead and light as a feather.